Hi, I would like to create a halftone image using a custom shape in the "Halftone Screen" dialog box. i.e. using a custom shape I created instead of the standard "round" "diamond" etc. Basically what I want to know is - if it is possible - how does one create a custom .AHS file containing a custom shape you created so as to create a halftone image.

Unfortunately no. Saving an .AHS file using the existing options is not a problem. The problem is you are restricted to the default shapes that photoshop provides. I'm trying to save one with a custom shape I created. But thank you.

Hm, interesting... You used to be able to save .ahs files from within the Options section of the Print with Preview dialog, but I don't see that capability with the current Photoshop (CS5). I never noticed that it vanished.

Hmmm... thanks guys, these are all in the right direction it seems. But unfortunately that still leaves the problem of getting the custom shape "into" the dialog box for use. I'm aware that you can create .AHS files using the above posted dialog box (posted by RénéG), but all that does is save a preset with values you entered, and does not allow for your own custom-made shapes to be used in the halftone image. :/

I created my own, preset pattern, in 5 levels of density. These are shown on the left, below.

Then I developed a set of 5 .axt files. (Made in the Select>Color Range... box.) These files, when activated, individually select areas of an image, based on density. (The darkest areas are selected by one .axt file, the next level by another file, and so on.)

Then I opened the jpeg of LBJ, and made an Action that runs each of the .axt files in turn. The Action also tells Ps to paint each selection with a corresponding preset (.pat) pattern. When all the .axt files are run and selections filled with .pat presets, the bitmapped image forms.